Man is a historical being : The realisations of the powers of human individuals living at any one time takes the cooperation of many generations (or even societies) over a long period of time. By contrast with humankind, every individual animal can and does do what for the most part it might do, or what any other of its kind might or can do that lives at the same time.
John RawlsIdeally citizens are to think of themselves as if they were legislators and ask themselves what statutes, supported by what reasons satisfying the criterion of reciprocity, they would think is most reasonable to enact.
John Rawls